I noticed no matter how pitch dark it gets my mirror doesnt dim, i see the bright shiny headlights pierce right into my retinas and i have to literally duck down to drive. sometimes it dims when sun is just setting but tonight at midnight i saw every shade of headlight through the mirror. owner manual doesnt show a way to turn it off and on, just says its automatic. before i go to dealership anything i can do to diagnose?

 

Not sure if your mirror is the same as mine, but I noted that the rear wing was casting a shadow over the light sensor on my mirror from headlights of following cars. Repositioning the mirror so it was out of that shadow (up, I think) solved the problem for me and it works fine now.

=Vic=

 

Same experience here, the pedestal spoiler blocks the light to the sensor in many cases.

 

This is good to know info right here.

 

I had the same problem when I first bought my car, it too has the big spoiler on the back. Mine didnt seem to be working so I brought it back to the dealer and he replaced it. AND HE BROKE MY WINDSHIELD! The car was 2 weeks old and he breaks my windshield trying to get the old mirror off. It was that glued to the glass. Of course he replaced the windshield and mirror. I notice it does the same thing. Sometimes it blocks the light but sometimes headlights behind me are bright. So I think it is the spoiler. I ahve not been able to find a position of the mirror to correct, however.

Joe C

 

So the problem mirror is isn't pointing to the back in right angle?

 

^ that sucks, most ppl, even dealers don't know how to remove them. they don't slide off the way they go on, there's a little hole in the bottom you put a small screwdriver in, pull it towards you, and it pops right off. one of my other cars had one and they suck, replaced it with a manual one. unfortunately the compass is in the mirror so that won't work if you change it